Pump and valve assembly



Sept. 14, 1965 WILKINSON ETAL 3,205,906

PUMP AND VALVE ASSEMBLY Filed July is, 1963 4 Sheets-Sheet 1 o {B V H INVENTORS 0/9/4445 1. MAMA/50M BY 620/965 Coo/(5,

Sept. 14, 1965 O. L. WlLKlNSON ETAL Filed July 16, 1963 PUMP AND VALVE ASSEMBLY INVENTORS 0/9/4415 A. MZ/W/VJOM 550/965 b. Coo/(i,

Sept. 14, 1965 o. WILKINSON ETAL 3,

PUMP AND VALVE ASSEMBLY 4 Sheets-Sheet 3 Filed July 16, 1963 My 2 W@ U KCM N M.E R WW w W 1. p6 F o United States Patent 3,2l5,tl5 PUMP AND VALVE ASSEMBLY ()rville L. Wilkinson, Northridge, and George H. Cooke, Granada Hills, Calif assignors, by direct and mesne assignments, to .I. I. Case Company, Racine, Wis., a corporation of Wisconsin Filed July 16, 1963, Ser. No. 295,334 2 Claims. (Cl. 137-246.22)

This invention relates to a pump and valve assembly and more particularly to a new and useful concrete pump employing a new and useful valve for controlling the fiow of concrete and the like having large aggregate composition.

Prior art concrete pumps are available wherein concrete is pumped by pistons reciprocating within large cylinders in such a manner that, as one piston discharges its contents, the other piston draws material from a hopper to be pumped during the next half cycle. Valving is provided between each cylinder, its material supply source and its discharge line to control flow. While generally satisfactory, such concrete pumps do have certain disadvantages.

One disadvantage resides in the fact that the valves employed can only seat by crushing any aggregate which may be in the path of the valve gate as it closes on its seat. This prevents satisfactory sealing and permits separation of concrete fines and liquid from the aggregate. Separation of the fines and liquid from the aggregate leaves the aggregate in a mass to block the machine and interrupt the pumping cycle.

Another disadvantage resides in the fact that air sometimes leaks passed the delivery piston on the suction stroke causing some separation of fines and liquid from the aggregate.

Yet another disadvantage resides in the fact that prior art portable concrete pumps can not handle a satisfactory quantity of inch minus rock which necessitates using a lower strength, higher cost mix.

In view of the foregoing factors and conditions characteristic of pumps employed for pumping concrete, it is a primary object of the present invention to provide a new and useful concrete pump not subject to the disadvantages enumerated above and having a unique valving arrangement which satisfactorily seals aggregate-containing concrete efficiently, safely and expeditiously.

Another object of the present invention is to provide a pump for pumping concrete which incorporates a unique valving arrangement to control the fiow of concrete from a hopper to a pair of discharge lines discharging into a common manifold.

Still another object of the present invention is to provide an improved valve for controlling the flow of concrete in a conduit.

A further object of the present invention is to provide a portable-concrete pump which can pump concrete mixes having larger aggregate, less sand, less water and less cement than can be pumped with prior art device.

A still further object of the present invention is to provide a valve for controlling the flow of concrete in a conduit wherein the valve includes a resilient nose portion which is adapted to close upon and encompass aggregate or other material upon which it seats without damaging the valve or the material while effecting a satisfactory seal.

According to the present invention, a portable concrete pump employs a pair of pistons which reciprocate in large cylinders. As one cylinder is discharging its con tents, the other cylinder is being loaded with material to be pumped during the next half cycle. Appropriate valving is provided so that the outflow of material into a common manifold from each delivery cylinder is essentially continuous.

Actuation of the pistons within the Fatented Sept. 14, 1965 "ice cylinders is accomplished by hydraulic rams. A common hopper is employed to supply the material to the cylinders through a unique valving arrangement of the present invention. When one cylinder is being loaded with material from the hopper, its discharge line to the manifold is closed and its line to the hopper is open. While the other cylinder is discharging, its line to the hopper is closed and its line to the manifold is open.

The hydraulic rams which actuate the pistons in the delivery cylinders are interconnected in such a manner that one ram extends as the other retracts and vice versa. Travel limit switches are employed to achieve cycling of the delivery pistons by having each piston actuate a switch when it reaches the end of its cylinder-filling or loading stroke. The travel limit switch completes an electrical circuit to one solenoid of a solenoid-actuated four-way hydraulic valve which responds to pressurize the hydraulic ram of a corresponding delivery piston and connect the opposite hydraulic ram to a hydrauilc reservoir. When the opposite delivery piston reaches the end of its travel, it actuates its travel limit switch which, in turn, operates the other solenoid of the four-way hydraulic valve. The valve then responds to pressurize the hydraulic ram of the corresponding delivery piston and townnect the other ram to the hydraulic reservoir. Actuation of the travel limit switches also simultaneously operates the material loading and discharge control valves in the appropriate configuration to permit pumping into the common manifold as described above.

The material flow control valves are actuated by hydraulic, double-acting cylinders. A dual-stack, solenoidactuated four-way hydraulic control valve is employed to activate the four, double-acting hydraulic cylinders.

The valves which control flow from the material supply hopper to the common manifold each includes a rubber nose portion which envelopes large aggregate when the valve is seated thereby effectively sealing the flow conduits to provide a positive shut oil.

A rinse tank is mounted between the pumping cylinders and is connected to the non-deliver or back side of the delivery cylinders to supply fluid, such as water or mineral oil, to the back side of the delivery cylinders to prevent air from leaking past the cylinders, to dilute any material passing behind the delivery pistons, to lubricate the seals on the delivery piston and to generally assist the seals on the back side of the delivery piston in their physical sealing during the fill stroke.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings, in which:

FIGURE 1 is a diagrammatic view of a concrete pump of the present invention;

FIGURE 2 is a partial elevational view on an enlarged scale, with parts shown in cross-section, of a portion of the device of FIGURE 1;

FIGURE 3 is a vertical cross-sectional view taken along line 3-3 of FIGURE 2;

FIGURE 4 is a transverse cross-sectional view, on an enlarged scale, of one of the valves of FIGURE 1 shown in a first operating position;

FIGURE 5 is a transverse cross-sectional view similar to FIGURE 4 showing the valve in transit to its seating position;

FIGURE 6 is a transverse cross-sectional view similar to FIGURE 4 showing the valve in a seated position;

FIGURE 7 is a transverse cross-sectional View taken along line '77 of FIGURE 6;

FIGURE 12 is a transverse cross-sectional view taken along line 1212 of FIGURE 10.

Referring again to the drawings, and more particularly to FIGURE 1, the pump and valve assembly constituting the presentinvention, generally designated 10', includes a pair. of delivery pistons 12 and 14 which are reciprocally mounted in delivery cylinders 16 and 18, respectively. A first conduit 2% places the cylinder 16 in communication with a material supply hopper 22 and a second conduit 24 places the cylinder 16 in communication with a Y- connection 26 having a discharge manifold 28. A third conduit 31) places the cylinder 18 in communication with the hopper 22 and a fourth conduit 32 connects the cylinder 18 to the Y-connection 26. Thus, the pistons 12 and 14 both discharge material which is drawn from the hopper 22, in a manner to be hereinafter described, into the common manifold 28. A supply line, not shown, may be connected to the manifold 28 so that the material, such as concrete or the like, pumped from the hopper 22 may be discharged at a remote location. The pistons 12 and 14 are reciprocated within the cylinders 16 and 18, respectively, through means to be hereinafter described, in such a manner that, as one piston moves to the right, the other piston moves to the left, as viewed in FIGURE 1. As a piston moves to the left, it draws concrete or other material from the hopper 22 through a respectivedischarge port 34 into a respective cylinder. As a piston moves to the right, it discharges the material drawn from the hopper on a previous back stroke out the Y-connection 26 and manifold 28. A scavenging horn 36 is connected to the front face of each piston to clear material from the junction of the lines from the hopper 22 and the discharge lines. A tail rod 38 is connected to the rear face of each piston. for the piston 12 extends through a partition 39 into a first cylinder 40 and the tail rod 38 for the piston 14 extends through a partition 39a into a second cylinder 42. The tail rods 38 are connected topistons 44- and 46, respectively. The pistons 44 and 46 and the cylinders 41) and 42 comprise hydraulic rams 48 and 49, respectively. A first hydraulic supply line 59 connects the upstream end 51 of ram 48 to a solenoid-controlled four-way valve 52 and a second hydraulic supply line 54 connects the upstream end 55 of the ram 49 to the valve 52. The downstream ends 56 of the rams 48 and 49 are interconnected with a common hydraulic supply line 57.

A pair of inlet valves 58 and 60 control the flow of material from the hopper 22 to the pistons 12 and 14,

respectively and a pair of discharge valves 62 and 64 control the flow of material through the discharge lines 24 and 32, respectively. The valves 58, 60, 62 and 64 each includes a tail-rod 68 which extends through an end cap 70 into a hydraulic cylinder 72. Each tail-rod 68 is connected to a piston 74 which is reciprocally mounted in its respective cylinder 72. Each piston 74 includes an upstream face 75 and downstream face 76. When the upstream faces 7 S are pressurized with hydraulic fluid, their associated valves will seat in their respective conduits to interrupt the flow of material therethrough. When a downstream face 76 is pressurized, its associated valve is opened. When piston 12 is moving to the left, as viewed in FIGURE 1, on its suction or fill stroke, valve 58 will be opened to permit flow of material from hopper 22 through a respective outlet 34 into the cylinder The tail rod 38 16 and valve 62 will be closed in conduit 24. Simultaneously, piston 14 will be moving to the right, as viewed in FIGURE 1, on its discharge stroke and valve 611 wiil be seated in conduit 36 to prevent flow of material from cylinder 13 into the hopper 22 and valve 64 will be opened to permit material from cylinder .18 to discharge through the discharge conduit 32 into the manifold 23.. Thus, valves 58 and 64 may be open at the same time and valves 61) and 62 may be seated at the same time and vice versa. This is accomplished by connecting the downstream faces 76 and upstreamfaces 75 of the valves 58 and 64 together with common hydraulic supply lines 78 and 89, respectively and by connecting the downstream faces 76 and the upstream faces '75 of valves 61) and 62 together with hydraulic supply lines 82 and 3d, respectively. Flow of hydraulic fluid to the valves 58, 69, 62, and 641 is controlled with a solenoid-controlled, dualstack, four-way valve 86. Hydraulic-fluid conducting lines 88, 9t 92 and 94 connect the common lines 78, 80, 82 and 841, respectively, to the valve 86.

A hydraulic reservoir 96 is provided to store the hydraulic fluid employed to-actuate the pistons 12 and 14 and the valves'58, 60, 62 and 64. While the reservoir 96 is shown schematically in FIGURE 1 as being separated from the hopper 22, the reservoir 96 actually oncompasses hopper 22, as shown in FIGURES 2 and 3, to conserve space and add rigidity to the hopper so that the concrete or other material 98 in the hopper 22 will cool the hydraulic fluid 100 in the reservoir 96. A first hydraulic-fluid return line 102 connects the valve 86 to the reservoir 96 through a control valve 103 and a sec- 0nd hydraulic-fluid return line 104 connects the valve 52 to the reservoir 96 through. a control valve 105. A line 106 connects the control valve 52 to the return line 104 so that any internal leakage within the valve 52 will return to the reservoir 96. Hydraulic fluid is drawn from the reservoir 96 through a first conduit 168, a control valve 109,, a second conduit 110, a filter 112, and a third conduit 114. The third conduit 114 discharges directly into the intake side of a hydraulic-fluid delivery pump 116 and a branch line 118 connects the third conduit 114- to the intake side of a control, hydraulic-fluid pump 12%. A first hydraulic-fluid supply line 122 connects the discharge side of the control pump to the valve 86 and a second hydraulic fluid supply line 124 connects the discharge side of the delivery pump 116 to the valve 52. A pump-case drain 126 connects the delivery pump 116 to the return line 1041 and a branch pumpcase drain 127 connects the control pump 120 to the pump-case drain 126.

A prime mover 128 supplies power to the pumps 116 and .120 through a flexible coupling 129 and shafts 130 and 131. A hydraulic accumulator 132 is connected in parallel with the control pump 126 through a line 133 and serves to supply hydraulic power to valve 86 at very high flow rates for short periods.

A rinse tank 134 is mounted between the delivery cylinders 16, and 18 and includes a surge chamber 135 which is vented to atmosphere. A pair of lines 136 and 136a place the tank 134 in fluid communication with the cylinders 16 and 18, respectively, so that the portion of the cylinders 16 and 18 between the rear faces of pistons 12 and 14 and the partitions 39 and 39a may be filled with liquid from the rinse tank 134. As the pistons reciprocate, the liquid will, of course, move back and forth between the tank 134 and the cylinders 16 and 18. A drain 137 is provided in the bottom of each cylinder adjacent the partitions 39 and 39a and a drain 138 is provided in the tank 134 so that the rinse liquid may be drained to waste when desired. The rinse liquid prevents air from leaking past the delivery pistons on their suction strokes and dilutes any material leaking past the delivery pistons. The fluid also lubricates the seals on the delivery pistons which is especially desirable during the filling or loading portion of the pumping cycle. The,

fluid used may be plain water or water having soluble oil added thereto. A mineral oil and like liquids may also be used. When operation of the pump 16 is terminated for any extended length of time, such as the end of a working day, the drains 137, 137a and 138 are preferably opened so that the fluid may flow out, thus removing any diluted materials which may have leaked past the delivery pistons 12 and 14.

The solenoids, to be hereinafter described, of values 52 and 86 are controlled through an electrical switching system including a latching relay 140 having a pair of coils 142 and 144 and four, single-pole, double-throw switch blades 145, 147, 148 and 149. A soft iron rod or core 150 is connected to the blades 146149 and extends into the coils 142 and 144. When the coil 144 is energized, the rod 150 will move to the right, as viewed in FIGURE 1, so that the blades will be closed on contacts 15%, 151, 152 and 153, respectively, as shown in FIGURE 1. When the coil 142 is energized, the rod 150 is drawn to the left, as viewed in FIGURE 1, swinging the blades 146- 149 into engagement with the contacts 154, 155, 156 and 157, respectively. A lead 158 connects the coil 144 to a lead 159 which, in turn, connects the coil 142 through a switch blade 1611 and a fuse 162 to a source of power comprising a storage battery 163. A lead 164 connects coil 142 to a blade 165 of a reversing switch 166 and a lead 167 connects the coil 144 to a blade 168 of the reversing switch 166. A third blade 169 of reversing switch 166 is connected by a lead 1'71) to the contacts 154 and 155 in the latching relay 140. A fourth blade 171 of the reversing switch 166 is connected by a lead 172 to the contact 151 of the latching relay 140. The blades 165, 169, 171 and 168 are connected to a rod 173 which may be positioned as shown in FIGURE 1 to close blades on contacts 174, 175, 176 and 177, respectively. The rod 173 may be moved-to the right as viewed in FIGURE 1, to bring the blades 165, 169, 171 and 168 into engagement with contacts 178, 179, 181 and 181, respectively.

The latching relay 140 is controlled by a pair of delivery-piston, travel limit switches 182 and 183 which are closed by the pistons 12 and 14, respectively, when they reach the end of their travel to the left, as viewed in FIGURE 1. A lead 184 connects the switch 182 to the contact 174 and a lead 136 connects the switch 133 to the contact 177.

A manually-operated push-button switch 187 is connected in the circuit with the switch 182 so that the switch 182 may be overridden manually when desired. A similar push-button switch 183 is connected in the circuit with the switch 183 for overriding it.

The latching relay 140 controls the operation of the valves 52 and 86 by actuating their respective solenoids through a number of different circuits which will now be described. A first solenoid 189 of valve 52 is connected by a lead 190 to the contact in reversing switch 166 and a second solenoid 191 in switch 52 is connected by a lead 192 to the contacts 176 and 179. A first solenoid 193 in the switch 86 is connected by a lead 194 to the contacts 156 and 157 in the latching relay 140. A second solenoid 195 in switch 86 is connected by a lead 196 to a lead 198 which, in turn, connects a third solenoid 199 to the terminals 152 and 153 in the latching relay 140. A fourth solenoid 209 in the valve 86 is connected by a lead 2131 to the lead 194.

A first indicating lamp 2112 is connected by a lead 2133 to the contacts 175 and and a second indicating lamp 204 is connected by a lead 205 to the contacts 179 and 176. The indicating lamps 292 and 204, when energized, indicate which discharge line is supplying material to the manifold 28.

A master control switch 2% includes the blade 160 previously mentioned and a second blade 207. A third indicating lamp 208 is connected by a lead 269 to the switch 2116 and indicates when the master switch is closed so that the system may be energized. A first start- Cir stop switch 210 is connected by a lead 211 to the switch 2196 and by a lead 213 to a jack 214 which, in turn, is connected by cables 215 and 216 to a second start-stop switch 217. The cables 215 and 216 may be of any desired length so that the switch 217 may be located at the discharge end of a line, not shown, discharging concrete from the manifold 23 to a point of application. Thus, the operator handling the discharge line can control the outflow of the material from the remote point of application. A circuit is completed through the jack 214 and the start-stop switch 210 by a lead 218 which connects the jack 214 to the blades 146 and 147 of the latching relay 140.

The control valves 58, 6t 62 and 64 are important features of the invention because they permit controlling the flow of a material, such as concrete, containing large particles, such as aggregate 98a (FIGURE 3) by forming an effective seal in a conduit without crushing the aggregate 98a or damaging the valve member. Referring now to FIGURES 2-9, these Valves may be of identical construction and each includes a valve body 219 in which a plug or gate 220 is slidably mounted. Each plug or gate 221) includes a core 221 (FIGURES 8 and 9) having external threads 222 at one end, a rubbergripping nose portion 224 at its other end and an annular darn 226 intermediate its ends. An annular skirt 227 is formed on core 221 adjacent the dam 226 and an annular groove 22% encompasses the core 221 intermediate the dam 226 and the skirt 227. The dam 226 prevents the nose plug 234 from becoming unseated from the groove 22% when the nose plug 234 is compressed by the seating of gate 228.

The nose portion 224 includes transverse bores 2313 and 232 which lie at right angles to each other. The resilient nose plug 234, which may be made of gummed rubber or a suitable synthetic material such as polybutadiene, is molded to the core 221 in such a manner that the nose plug 234 firmly grips the annular groove 228 and the transverse bores 23211 and 232. The skirt 227 forms a recess 236 with the core 221 to accommodate a pressure ring 240 which encompasses the core 221 with an end 242 slidably mounted in the recess 236. The pressure ring 241) includes a grease passage way 244 which communicates with a similar passageway 246 contained in core 221. A grease fitting 247 is connected to the passageway 246 so that a suitable lubricant, such as Water pump grease, may be supplied to the periphery of the gate 220. The grease is distributed about the periphery of plug or gate 221 by a lantern ring 248 which encompasses pressure ring 240 and has an annular channel 249 communicating with passageway 244. A plurality of apertures 2513 are spaced about the periphery of ring 248 to admit the grease from channel 249 to the periphery of gate 221).

A first set of packing rings 251 encompasses the pressure ring 2411 between the lantern ring 248 and an annular land 252 formed on the ring 240 and a second set of packing rings 253 encompasses the pressure ring 240 between the lantern ring 245 and the skirt 227. A nut 254 threadedly engages the threads 222 and bears against the pressure ring 2419. The packing rings 251 and 253 prevent material, whose flow is to be controlled by the plug 220, from flowing past the plug 221), and are compressed between the skirt 227 and the land 252 by tightening the nut 254 against the pressure ring 240 causing it to slide further into the recess 236. The material whose flow is being controlled and the lubricant are prevented from flowing into the recess 236 by an O-ring 255 which encompasses the end 242 and bears again-st the inner wall of the skirt 227. The nut 254 may be tightened to compensate for wear on the packing rings 251 and 253. The cylindrical portion of core 221 which engages the valve body during reciprocation of the valve includes the skirt 227 and the nut 224 and the length of this cylindrical portion is greater than its diameter in order to provide sufficient bearing area with the valve body to resist the pressure developed on the nose plug when in the closed position of FIGURE 7. Also the length of the nose portion 224 is more than one-half the total length of the nose plug 234 to prevent the nose plug from twisting off the nose portion when subjected to high concrete pressures.

A modified valve 58a is shown in FIGURES ll2 as controlling the flow of material through a conduit a and is substantially similar to the valve 58 previously described except that it is of a square configuration. The valve 58a includes a square body portion 21% in which a gate 22% is slidably mounted. The gate 229a includes a core 221a having transverse bores 230a and 232a. A tail rod 58a threadedly engages the core 221a. A resilient nose portion 234a is molded to the core 221a and is of sufficiently resiliency that it will seat against the conduit 20a and envelope any aggregate which may be trapped between the plug or gate 220a and the conduit 20a.

Operation of the device will be described in connection with FIGURE 1. Assuming that the hooper 22 is filled with a material, such as concrete, to be pumped by the pump 11) and that the prime mover 128 is energized to pressurize the hydraulic system, then switches 206 and 211 may be closed to energize the solenoids of valves 52 and 86. Assuming further that, when the electrical system is energized, the reversing switch 166 and the latching relay 149 are in the positions shown in FIGURE 1. When the electrical system is energized, current will flow from the battery 163 to the solenoid 191 through the fuse 162, the blade 207 of switch 206, lead 211, switch 211 lead 213, jack. 214', lead 218, blades 146 and 147 of latching relay 140, lead 172, blade 171, contact 176 and lead 192. Current also flows from battery 163 to the solenoids 195 and 199 in valve 86 through fuse 162, blade 16%, lead 159, lead 158, blades 143 and 149 and leads 198 and 196.

Energization of solenoid 191 positions valve 52 in such a manner that fluid under pressure from pump 116 flows from line 124 through valve 52, and line 5 1 into ram 49 pressurizing cylinder 42, causing piston 46 to move to the right, as viewed in FIGURE 1. Piston 46 forces hydraulic fluid out end 56 of cylinder 42, through line 5'7 and into the end 56 of cylinder 40. This pressurizes ram 48 causing piston 44 to move to the left, as viewed in FIGURE 1, exhausting hydraulic fluid out end 51 of cylinder 4-11 through line 50, valve 52, return line 104 and valve 105 into reservoir 96.

Energization of solenoids 195 and 199 positions valve 86 in such a manner that hydraulic fluid under pressure from line 122 flows through valve 86, line 94 and line 84 to pressurize faces 75 of valves 61} and tSZforcing the valves to seat in conduits 311 and 24, respectively. Fluid under pressure from line 122 also flows through valve 86, lines 88 and 78 into valves 58 and 64 pressurizing faces '76 of the respective pistons thereby opening the valves 58 and 64. The valve 86 is also positioned in such a manner that return fluid will flow from the faces 75 of pistons 74 in valves 58 and 64 through lines 81) and 90, valve 86, return line 102 and valve 103 into the reservoir 96. With the valves thus positioned, the movement of piston 12 to the left, as viewed in FIGURE 1, by ram 48 draws material from hopper 22 through outlet 34, conduit 20, and into cylinder 16 filling it. As piston 14 simultaneously moves to the right, as viewed in FIGURE 1, due to the force exerted by ram 49, material in cylinder 18 is forced through conduit 32 and Y- connection 26 into manifold 28. The scavenger horn 36 on piston 14 clears the material from the juncture of conduits 311 and 32. As delivery piston 12 moves to the left, it will also force rinse liquid from cylinder 16 through line 136, tank 134, line 135a and into cylinder 18 behind the piston 14- to prevent air from leaking past pistons 12-.and 14 and to dilute any material that might have leaked past the cylinder 14.

When piston 12 reaches the end of its travel to the left, it closes travel limit switch 182 completing a circuit through lead 184, contact 174, blade 165, lead 164, coil 14-2., lead 159, blade 169, fuse 162 and battery 163. This energizes coil 142 drawing the soft iron core 159 to the left, as viewed in FIGURE 1, to bring the blades 146, 147, 143 and 149 into engagement with the contacts 154, 155, 156, and 157, respectively. This energizes solenoids 189 in valve 52 and solenoids 193 and 200 in valve 86 by placing the leads 199, 194, and 201 in a circuit with battery 163 through the latching relay 14-h.

Energization of solenoid 189 positions valve 52 in such a manner that fluid under pressure from line 124 will be directed through the valve 52 and line into the end 51 of ram 48 pressurizing the piston 44 in such a manner that the ram 48 will cause delivery piston 12 to move to the right as viewed in FIGURE 1. The solenoid 189 will also position the valve 52 in such a manner that return fluid flowing from the ram 48 through line 57 pressurizes piston 4-6 causing it to move to the left, as viewed in FIGURE 1, exhausting the fluid from cylinder 42 through line 54, valve 52, line 104, and valve 105 into reservoir 96.

Energization of solenoid 193 will cause valve 85 to be positioned in such a manner that fluid under pressure in line 122 flows through valve .86, lines 92 and 82 pres surizing valves 60 and 62 on the faces 76 of their respective pistons to unseat the valves. The valve 86 is also positioned in such a manner that return fluid from the valves 60 and 62 flows through lines 84 and 94, valve 86, line M2, and valve 103 into the reservoir 96. Energization of the solenoid 200 positions valve 86 in such a manner that fluid under pressure in'line 122 also flows through valve 86, lines 99 and 80, into cylinders 72 to pressurize faces of valves 58 and 64 causing them to seat in their respective conduits and through valve 86, lines 92 and 82 into cylinders 72 to pressurize the faces 76 of valves 64 and 62 causing them'to open. Thus, the valves 61) and 62 will open and'valves 58 and 64 will be closed so that movement ofthe piston 12 to the right, as viewedin FIGURE 1, will force material previously drawn into the cylinder 16 out the cylinder 16 into conduit 24, Y-connection 26 and out manifold 28. Simultaneously, piston 14 moves to the left, as viewed in FIGURE 1, drawing material from hopper 22, through opening 34- and line 30 into the cylinder 18 filling it with material to be delivered on the next stroke. Movement of piston 14 to the left forces the rinse liquid behind the piston in cylinder 18 out cylinder 18 through line 136a, rinse tank 134, and line 136 into the cylinder 16 behind its piston keeping the area behind piston 12 in cylinder 16 filled with rinse liquid as the piston 12 moves to the right. When the piston 14 reaches the end of its travel to the left, as viewed in FIGURE 1, it closes its travel limit switch 183, completing a circuit through lead 186, contact 177, blade 168, lead 167, coil 144, lead 158, lead 159, blade'1dt), and fuse 162 to battery163. This energizes coil 144 drawing soft iron core 159 to the right, as viewed in FIGURE 1, swinging blades 146, 147, 148 and 149 into engagement with the contacts 150, 151, 152 and 153 to again energize the solenoids 191, and 199 preparing the pump 10 for its next one-half cycle of operation.

Should it be desired to reverse the above sequence of operation, the reversing switch 166 may be adjusted for such operation by sliding the rod 173 to the right, as viewed in FIGURE 1, to bring the blades 165, 169, 171, and 168 into engagement with the contacts 178, 179, 189 and 181, respectively. This reverses the circuits through the latching relay 14%. The travel limit switch 182 may be manually overridden by depressing button 187 to bypass the circuit to coil 142. Similarly, the limit travel switch 183 may be manually overridden by depressing the button 183 to by-pass the coil 144 in latching relay 149.

The accumulator 132 insures immediate hydraulic response through the valve 86 by making a high flow of fluid available at all times so that fluid will flow through the valve 86 the instant the solenoids therein are energized.

The above described cycle of operation will repeat itself continuously as long as the electrical circuit is energized. The circuit may be de-energized to interrupt the flow of material from hopper 22 from a remote location by assembling jack 214 and then opening switch 217 to interrupt the circuit from the battery 163.

While the particular concrete pump and valves herein shown and described in detail are fully capable of attaining the objects and providing the advantages hereinbefore stated, it is to be understood that they are merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction or design herein shown other than as defined in the appended claims.

What is claimed is:

1. A valve for controlling the flow of material containing discrete particles comprising:

a valve body having a seat;

a valve gate reciprocally mounted in a cylindrical opening in said body;

said valve gate comprising a core of rigid material having a cylindrical portion and a reduced nose portion at one end thereof;

a resilient nose plug covering said nose portion and secured thereto;

said nose plug comprising a dome-shaped end surface connecting with a cylindrical surface surrounding said nose portion, said cylindrical surface having the same diameter as said cylindrical portion of said core to be coextensive therewith;

said cylindrical portion being in full engagement with said cylindrical opening when said valve is closed by moving said nose plug against said seat and having a length greater than its diameter to provide sufficient bearing area to resist the pressure applied to said nose plug when the valve is closed;

said nose portion extending into said nose plug by a distance of more than half the length of said nose plug against pressure applied thereto when in said closed position; and

an annular dam extending outwardly from the end of said nose portion adjacent said cylindrical portion of said core, said dam comprising an annular wall separated from said cylindrical portion by a cylindrical groove; the diameter of said wall being smaller than said cylindrical surface of said nose plug so that said nose plug passes around said wall and is anchored in said groove.

2. A valve as defined in claim 1 having a depression in the surface of said cylindrical portion;

a grease distributing ring located within said depression and having apertures in communication with grease supply passage means in said core; and

packing means located in said depression on opposite sides of said ring.

References Cited by the Examiner UNITED STATES PATENTS 2,366,417 1/45 MacMillin 103-49 X 2,485,208 10/49 Longenecker 103204' 2,690,715 10/54 Pope 10349 2,962,047 11/60 Obermaier 137-525 2,998,781 9/61 Triebel 103--49 3,068,806 12/62 Sherrod 103169 3,077,204 2/63 Bennett et a1. 137525 3,091,260 5/63 Milanovits et al 251-191 X FOREIGN PATENTS 520,456 1/5 6 Canada. 870,187 6/61 Great Britain.

ROBERT M. WALKER, Primary Examiner.

LAURENCE V. EFNER, DONLEY J. STOCKING,

Examiner. 

1. A VALVE FOR CONTROLLING THE FLOW OF MATERIAL CONTAINING DISCRETE PARTICLES COMPRISING: A VALVE BODY HAVING A SEAT; A VALVE GATE RECIPROCALLY MOUNTED IN A CYLINDRICAL OPENING IN SAID BODY; SAID VALVE GATE COMPRISING A CORE OF RIGID MATERIAL HAVING A CYLINDRICAL PORTION AND A REDUCED NOSE PORTION AT ONE END THEREOF; A RESILIENT NOSE PLUG COVERING SAID NOSE PORTION AND SECURED THERETO; SAID NOSE PLUG COMPRISING A DOME-SHAPED END SURFACE CONNECTING WITH A CYLINDRICAL SURFACE SURROUNDING SAID NOSE PORTION, SAID CYLINDRICAL SURFACE HAVING THE SAME DIAMETER AS SAID CYLINDRICAL PORTION OF SAID CORE TO BE COEXTENSIVE THEREWITH; SAID CYLINDRICAL PORTION BEING IN FULL ENGAGEMENT WITH SAID CYLINDRICAL OPENING WHEN SAID VALVE IS CLOSED BY MOVING SAID NOSE PLUG AGAINST SAID SEAT AND HAVING A LENGTH GREATER THAN ITS DIAMETER TO PROVIDE SUFFICIENT BEARING AREA TO RESIST THE PRESSURE APPLIED TO SAID NOSE PLUG WHEN THE VALVE IS CLOSED; SAID NOSE PORTION EXTENDING INTO SAID NOSE PLUG BY A DISTANCE OF MORE THAN HALF THE LENGHT OF SAID NOSE PLUG AGAINST PRESSURE APPLIED THERETO WHEN IN SAID CLOSED POSITION; AND AN ANNULAR DAM EXTENDING OUTWARDLY FROM THE END OF SAID NOSE PORTION ADJACENT SAID CYLINDRICAL PORTION OF SAID CORE, SAID DAM COMPRISING AN ANNULAR WALL SEPARATED FROM SAID CYLINDRICAL PORTION BY A CYLINDRICAL GROOVE; THE DIAMETER OF SAID WALL BEING SMALLER THAN SAID CYLINDRICAL SURFACE OF SAID NOSE PLUG SO THAT SAID NOSE PLUG PASSES AROUND SAID WALL AND IS ANCHORED IN SAID GROOVE. 